1. Field of the Invention
The present invention relates to a method and apparatus for processing an automatic content recognition (ACR) service related to a broadcast program, and more particularly, to a method and apparatus for providing an additional service related to broadcast content in an ACR environment.
2. Discussion of the Related Art
As digital satellite broadcasting has been introduced, digital data broadcasting has appeared as a new supplementary service. An interactive data broadcast, which is a representative interactive service, may transmit not only a data signal but also an existing broadcast signal to a subscriber so as to provide various supplementary services.
A digital data broadcast may be largely divided into an independent service using a virtual channel and a broadcast-associated service via an enhanced TV (ETV). The independent service includes only text and graphics without a broadcast image signal and is provided in a format similar to an existing Internet web page. Representative examples of the independent service include a weather and stock information provision service, a TV banking service, a commercial transaction service, etc. The broadcast-associated service transmits not only a broadcast image signal but also additional text and graphic information. A viewer may obtain information regarding a viewed broadcast program via a broadcast-associated service. For example, there is a service for enabling a viewer to view a previous story or a filming location while viewing a drama.
In a broadcast-associated service of a digital data broadcast, an ETV service may be provided based on ACR technology. ACR means technology for automatically recognizing content via information hidden in the content when a device plays audio/video (A/V content) back.
In implementation of ACR technology, a watermarking or fingerprinting scheme may be used to acquire information regarding content. Watermarking refers to technology for inserting information indicating a digital content provider into digital content. Fingerprinting is equal to watermarking in that specific information is inserted into digital content and is different therefrom in that information regarding a content purchaser is inserted instead of information regarding a content provider.
However, a conventional system for providing an interactive service via an ACR function has several restrictions.
If a content provider (or a broadcaster) transmits content for a real-time service and enhancement data (or additional data) for an ETV service and a TV receiver receives the content for the real-time service and the enhancement data through external input, the content for the real-time service may be received but the enhancement data may not be received.
In addition, if an existing ETV service is provided on an ACR system, intervention of a separate ACR server (or an ACR solution provider) is inevitably required. Therefore, there is a need for a receiver for performing an ACR function alone without a separate ACR server.
In addition, in watermarking technology for providing an ETV service, if the amount of information included in a watermark is large, quality of content in which a watermark is embedded may be deteriorated. Therefore, there is a limitation in efficient use of watermarking.
In addition, in fingerprinting technology for providing an ETV service, an external ACR server for recognizing content is additionally necessary and a content recognition result depends on the size of a reference set.